As issues continue for products using lithium-ion batteries, research into safer alternatives picks up speed

BY ANGELO VERZONI

Lithium-ion batteries once again made safety headlines as a new round of hoverboard recalls struck the market this holiday season.

In November, the United States Consumer Product Safety Commission (CPSC) announced recalls for about 14,000 of the two-wheeled, self-balancing motorized scooters. Several brands were affected, but all share the same problem: a lithium-ion battery that can overheat and catch fire or explode.

The recalled hoverboards join a growing list of products containing the potentially dangerous batteries—a list that includes earlier iterations of hoverboards, but also smaller products like cell phones. In 2016, nearly 2 million Samsung Galaxy smartphones were recalled after reports of fires and explosions related to failures of the handheld devices’ batteries. The CPSC notes, however, that these failures can be more dangerous when they involve larger batteries found in larger products like the hoverboards. In March 2017, for instance, two young girls died in a house fire in Pennsylvania sparked by a recharging hoverboard.

In recent years, the recalls and media reports have triggered a flood of research into how lithium-ion batteries could be improved or replaced to reduce the danger to consumers and others.

A study published in the journal Nature Energy in November touts “fire-extinguishing organic electrolytes” as one possible solution to lithium-ion battery woes. Conducted by researchers at the University of Tokyo, the study reports the use of an electrolyte made with trimethyl phosphate, a flame-retardant chemical, in a lithium-ion battery, which traditionally contains a carbon-based, flammable electrolyte. Similar efforts have in the past yielded new batteries that didn’t perform as well as traditional ones, but the Tokyo researchers say their battery offers performance “comparable or superior to that of [ones containing] conventional flammable carbonate electrolytes.” This is because the trimethyl phosphate–containing electrolyte has an “unusual passivation character,” or ability to prevent corrosion, the study says.

It’s promising research, and it comes on the tails of similarly optimistic studies. In April, for example, United States Navy researchers developed a zinc-ion battery with a non-flammable electrolyte with performance comparable to batteries that use lithium.

Fire Protection Research Foundation (FPRF) work has focused on the applications and fire hazards of current lithium-ion batteries rather than battery chemistry, said Casey Grant, director of the foundation. “The emergency response and fire protection communities must be ready to address new and different hazards, and to do so they need to be aware of the hazards associated with lithium-ion batteries most commonly being used today,” Grant said. Past FPRF reports have, for example, focused on the effectiveness of sprinkler systems to extinguish fires in lithium-ion battery storage facilities.

NFPA has also taken steps to educate the public about lithium-ion battery safety. NFPA has released safety tip sheets on lithium-ion batteries, and even hoverboards specifically, which can indicate possible warning signs including strange smells or a tendency to overheat. NFPA’s webpage on energy storage systems, includes resources on lithium-ion battery safety, such as tip sheets, research reports, and recent NFPA Journal articles.

ANGELO VERZONI is staff writer for NFPA Journal. Top Photograph: AP/Wide World